Biomaterial Database

Comparison of three methods for detection of group A streptococci in throat swabs. 1992

J P Anhalt, and B J Heiter, and D W Naumovitz, and P P Bourbeau

Department of Laboratory Medicine, Geisinger Medical Center, Danville, Pennsylvania 17822.

Group A streptococci are generally detected in throat swabs by (i) rapid antigen tests, (ii) conventional culture, or (iii) combinations of both. Direct fluorescent-antibody testing of a 2-h enrichment broth (FA/EN) was an accepted method for same-day results before the advent of rapid antigen tests. We compared FA/EN in Todd-Hewitt Broth (THB) with conventional culture and a rapid antigen test, TestPack Strep A (TPS). Nine hundred seventy specimens were evaluated in this study. Cultures were performed for 48 h on sheep blood agar (SBA) incubated aerobically and on a selective agar for group A streptococci (SSA) incubated in 5 to 10% CO2. Following a 2-h incubation, the fluorescent-antibody test was performed. A subculture of the centrifuged sediment from the THB enrichment was also done. In comparison with a positive culture on SBA or SSA or subculture of the THB pellet, the sensitivities and specificities of the different methods were as follows: SBA, 92 and 100%; SSA, 92 and 100%; TPS, 68 and 99%; FA/EN, 88 and 98%. The FA/EN method offers the potential for definitive finalized reports on the same day as specimen collection with greater sensitivity than TPS. This study included sequential plating and rapid antigen testing of a single swab. In a separate set of experiments to validate this study design, it was shown that recovery of streptococci from swabs plated sequentially on five plates did not vary with the order of plating and the actual proportion of organisms recovered from a swab on a single plate was only 1%.

UI	MeSH Term	Description	Entries
D010612	Pharyngitis	Inflammation of the throat (PHARYNX).	Sore Throat,Pharyngitides,Sore Throats,Throat, Sore
D010614	Pharynx	A funnel-shaped fibromuscular tube that conducts food to the ESOPHAGUS, and air to the LARYNX and LUNGS. It is located posterior to the NASAL CAVITY; ORAL CAVITY; and LARYNX, and extends from the SKULL BASE to the inferior border of the CRICOID CARTILAGE anteriorly and to the inferior border of the C6 vertebra posteriorly. It is divided into the NASOPHARYNX; OROPHARYNX; and HYPOPHARYNX (laryngopharynx).	Throat,Pharynxs,Throats
D002648	Child	A person 6 to 12 years of age. An individual 2 to 5 years old is CHILD, PRESCHOOL.	Children
D005069	Evaluation Studies as Topic	Works about studies that determine the effectiveness or value of processes, personnel, and equipment, or the material on conducting such studies.	Critique,Evaluation Indexes,Evaluation Methodology,Evaluation Report,Evaluation Research,Methodology, Evaluation,Pre-Post Tests,Qualitative Evaluation,Quantitative Evaluation,Theoretical Effectiveness,Use-Effectiveness,Critiques,Effectiveness, Theoretical,Evaluation Methodologies,Evaluation Reports,Evaluation, Qualitative,Evaluation, Quantitative,Evaluations, Qualitative,Evaluations, Quantitative,Indexes, Evaluation,Methodologies, Evaluation,Pre Post Tests,Pre-Post Test,Qualitative Evaluations,Quantitative Evaluations,Report, Evaluation,Reports, Evaluation,Research, Evaluation,Test, Pre-Post,Tests, Pre-Post,Use Effectiveness
D005455	Fluorescent Antibody Technique	Test for tissue antigen using either a direct method, by conjugation of antibody with fluorescent dye (FLUORESCENT ANTIBODY TECHNIQUE, DIRECT) or an indirect method, by formation of antigen-antibody complex which is then labeled with fluorescein-conjugated anti-immunoglobulin antibody (FLUORESCENT ANTIBODY TECHNIQUE, INDIRECT). The tissue is then examined by fluorescence microscopy.	Antinuclear Antibody Test, Fluorescent,Coon's Technique,Fluorescent Antinuclear Antibody Test,Fluorescent Protein Tracing,Immunofluorescence Technique,Coon's Technic,Fluorescent Antibody Technic,Immunofluorescence,Immunofluorescence Technic,Antibody Technic, Fluorescent,Antibody Technics, Fluorescent,Antibody Technique, Fluorescent,Antibody Techniques, Fluorescent,Coon Technic,Coon Technique,Coons Technic,Coons Technique,Fluorescent Antibody Technics,Fluorescent Antibody Techniques,Fluorescent Protein Tracings,Immunofluorescence Technics,Immunofluorescence Techniques,Protein Tracing, Fluorescent,Protein Tracings, Fluorescent,Technic, Coon's,Technic, Fluorescent Antibody,Technic, Immunofluorescence,Technics, Fluorescent Antibody,Technics, Immunofluorescence,Technique, Coon's,Technique, Fluorescent Antibody,Technique, Immunofluorescence,Techniques, Fluorescent Antibody,Techniques, Immunofluorescence,Tracing, Fluorescent Protein,Tracings, Fluorescent Protein
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man
D000942	Antigens, Bacterial	Substances elaborated by bacteria that have antigenic activity.	Bacterial Antigen,Bacterial Antigens,Antigen, Bacterial
D001431	Bacteriological Techniques	Techniques used in studying bacteria.	Bacteriologic Technic,Bacteriologic Technics,Bacteriologic Techniques,Bacteriological Technique,Technic, Bacteriological,Technics, Bacteriological,Technique, Bacteriological,Techniques, Bacteriological,Bacteriologic Technique,Bacteriological Technic,Bacteriological Technics,Technic, Bacteriologic,Technics, Bacteriologic,Technique, Bacteriologic,Techniques, Bacteriologic
D012680	Sensitivity and Specificity	Binary classification measures to assess test results. Sensitivity or recall rate is the proportion of true positives. Specificity is the probability of correctly determining the absence of a condition. (From Last, Dictionary of Epidemiology, 2d ed)	Specificity,Sensitivity,Specificity and Sensitivity
D013290	Streptococcal Infections	Infections with bacteria of the genus STREPTOCOCCUS.	Group A Strep Infection,Group A Streptococcal Infection,Group A Streptococcal Infections,Group B Strep Infection,Group B Streptococcal Infection,Group B Streptococcal Infections,Infections, Streptococcal,Infection, Streptococcal,Streptococcal Infection